Question: Suppose the circumference of a circle is ${12\pi}$. What is its area?
Explanation: ${c = 12\pi}$ ${K = 36\pi}$ First, find the radius: $r = c/2\pi = {12\pi}/2\pi = {6}$ Now find the area: $K = \pi r^2$, so $K = \pi \cdot {6}^2 = {36\pi}$.